Thallus: crustose, composed of scattered, warts, that develop into soredia, mostly entirely sorediate, rarely esorediate areoles: strongly convex, 0.1-0.2 mm in diam., irregular in outline and often incised at the margins surface: white, dull, sorediate soredia: same color as esorediate part or bluish gray, 20-50 µm in diam., not in well delimited, confluent soralia covering the whole thallus Apothecia: rounded to deformed, single, sessile with a constricted base, 0.2-0.55(-0.75) mm wide disc: reddish brown, plane to moderately convex margin: weakly prominent, flat or excluded in old apothecia, slightly lighter than disc exciple: brown, lighter below than above, laterally c. 35 µm wide, basally 75 µm wide, composed of radiating hyphae with 1-1.2 wide lumina and apical cells with 2.5-4 µm wide lumina epihymenium: orange brown, composed of paraphysal tips and granules, 10-15 µm thick hymenium: hyaline, c. 50 µm tall; paraphyses: basally hyaline, with lumina c. 0.7 µm wide, apically with brown walls, 2.5-4 µm wide, weakly branched and anastomosing subhymenium and hypothecium: hyaline, each c. 50 µm thick asci: clavate, Bacidia-type with an I+ blue tholus containing an indistinct, lighter blue, tapering axial body, 8-spored ascospores: hyaline, simple, globose, 5-7.5 µm wide Pycnidia: not seen Spot tests: thallus K-, C-, KC-, P-, UV+ white Secondary metabolites: divaricatic acid. Substrate and ecology: on bark of Pinus ponderosa between 1950 and c. 2500 m World distribution: North America and Europe Sonoran distribution: mountains of Arizona. Notes: Only two Sonoran collections are known, one of which is esorediate and resembles Lecanora boligera, that also has globose spores but is distinguished by having lobaric and fumarprotocetraric acids. The relationship of both taxa is in need of revision. Lecidea nylanderi is the only species treated here with globose spores and divaricatic acid.